Whetstone



FIG. 1 is a perspective view of a whetstone showing our design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a front view of the whetstone attached to a necklace.

The broken line showing of FIG. 8 is for environmental purposes only and forms no part of the claimed design. 

CLAIM The ornamental design for a whetstone, as shown and described. 